Tractors have several heat exchangers which form part or different cooling systems. For example, a heat exchanger, normally termed a radiator, is required for cooling water circulating in the engine. A second heat exchanger is used to cool oil circulating in the transmission system and a further heat exchanger is used to cool the engine charge air. The latter two heat exchangers are commonly referred to as coolers. All three of these heat exchangers, form a cooler block located at the front of the tractor so that a single electric or engine driven radiator fan can suck ambient air through all of them.
Since agricultural vehicles are usually operated in an environment with considerable air pollution, the vehicle's coolers need to be cleaned from time to time. To clean the coolers, they must first be separated from each other so that they are accessible from the rear. This, however, is not easy to put into practice in the case of agricultural vehicles, as the space available for the cooler block is severely restricted by the wheels and the frame as well as the front lifting gear and possibly necessary ballast weights.
This problem is addressed in US 2003/0168269 in which the cooler block contains at least a front cooler, a central cooler, and a rear cooler. The rear cooler is attached at a fixed position on the frame of the agricultural tractor and the central cooler can be moved, away from the rear cooler while the front cooler can also be moved away from the central cooler. The front cooler is suspended so that is can move sufficiently upwards and, if necessary, also forwards, that the central cooler can be swung away from the rear cooler unhindered to the side at about a right angle.
This arrangement is somewhat complicated owing to the fact that three coolers are arranged in series, one behind the other. However, as the area of the radiator for the engine coolant is normally larger than the area of the coolers for the transmission oil and the charge air, it is possible to simplify the construction of the cooler block by positioning the latter two coolers in the same plane as one another in front of the radiator so that air need only be sucked through two coolers arranged in series, not three.
FIG. 1 of the accompanying drawings shows a known cooler block in which the transmission oil cooler and the air charge cooler together form a cooler assembly 12 that is mounted for pivotal movement relative to a radiator 10, to allow the two to be separated for cleaning. On each side of the radiator 10, the cooler assembly 12 is supported by means of a spigot 14 that rests in a groove 16 in a top bracket 18 mounted on the radiator 10. To prevent the cooler assembly 12 from separating completely from the radiator 10, a lower bracket 20 is firmly secured to the cooler assembly 12 and it is formed with a groove 22 in the form of a circular arc centred on the spigot 14 which receives a pin 24 projecting from the side of the radiator 10. This mounting allows the cooler assembly to pivot about the spigot 14 through an angle determined by the length of the groove 22 but not to be lifted off the bracket 18.
This mounting has certain disadvantages, one being that the cooler assembly at its upper end can only pivot about the spigot 14, which does not create much separation between the cooler assembly 12 and the radiator 10 for cleaning purposes. Furthermore, when the lower end of the cooler assembly 12 is pivoted away from the radiator, stays or gas struts are needed to maintain it in the separated position. These gas struts may assist in the movement of the cooler assembly in one direction but they interfere with movement in the opposite direction. Furthermore, they can hinder access to the space created between the cooler assembly and the radiator for cleaning purposes.